v1.1.1: Chat Composer Lean Refactor

[arnaudassoumani-collab]

Parent epic: #14

Scope

• Split large ChatInput component into lean core and advanced sections
• Keep advanced controls behind explicit expand
• Condense quick actions into a focused menu
• Collapse SOCAkit panel by default

Acceptance

• Default composer is uncluttered and workflow-first
• Advanced controls remain available without regressions
• Sidebar layout is stable on desktop and narrow widths